Pancreatic adenocarcinoma (PDAC) is a remarkably aggressive malignancy associated with high rates of metastasis and poor therapy response. It is currently the 4th leading cause of cancer related deaths in developed countries and despite efforts to improve treatment options, the median overall survival remains <1 year. Therefore it is important to identify new targets that promote disease aggressiveness and therapy resistance. Our lab and others have previously identified the RNA-binding protein Musashi (Msi) as critical for the development of multiple malignancies. We have demonstrated that Msi2 is aberrantly upregulated during disease progression in chronic myeloid leukemia and inhibition of Msi2 results in a significant increase in overall survival in de novo mouse models of leukemia. However, it was unclear if Msi2 is important in the progression of solid tumors. In this regard, we tested for Msi2 expression in patient pancreatic cancer samples and determined that indeed protein expression increases during the onset and development of PDAC. By utilizing a genetic mouse model of pancreatic cancer crossed to Msi2-/- mice, we found that Msi2 blockade significantly slows tumor development and results in increased overall survival. Moreover, we determined that Msi2+ pancreatic cancer cells are enriched for tumor-propagating ability. These data suggest that Msi2 functionally contributes to PDAC progression. Therefore, we hypothesize that Msi2+ cells preferentially metastasize and survive chemotherapy. To test this we aim to (1) determine if Msi2+ tumor cells drive formation of metastasis and if Msi2 inhibition reduces metastatic burden, and (2) determine if Msi2+ cells are more resistant to chemotherapies and decipher the mechanisms by which they preferentially survive. The results of these studies have the potential to identify a key program in PDAC pathogenesis and define a subset of cells that specifically promote disease aggressiveness.

Public Health Relevance

The majority of pancreatic cancer patients present with extensive disease that is refractory to current therapy. Considering the 5-year survival rate is approximately 6%, these patients represent a significant unmet medical need. The goal of this proposal is to characterize a population of pancreatic cancer cells that specifically drive tumor progression and therapy resistance in order to better understand key pathways in the pathogenesis of this disease.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Predoctoral Individual National Research Service Award (F31)
Project #
5F31CA206416-02
Application #
9269057
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Schmidt, Michael K
Project Start
2016-04-01
Project End
2018-03-31
Budget Start
2017-04-01
Budget End
2018-03-31
Support Year
2
Fiscal Year
2017
Total Cost
Indirect Cost
Name
University of California San Diego
Department
Type
Schools of Medicine
DUNS #
804355790
City
La Jolla
State
CA
Country
United States
Zip Code
92093
Todoric, Jelena; Antonucci, Laura; Di Caro, Giuseppe et al. (2017) Stress-Activated NRF2-MDM2 Cascade Controls Neoplastic Progression in Pancreas. Cancer Cell 32:824-839.e8
Bajaj, Jeevisha; Konuma, Takaaki; Lytle, Nikki K et al. (2016) CD98-Mediated Adhesive Signaling Enables the Establishment and Propagation of Acute Myelogenous Leukemia. Cancer Cell 30:792-805
Fox, Raymond G; Lytle, Nikki K; Jaquish, Dawn V et al. (2016) Image-based detection and targeting of therapy resistance in pancreatic adenocarcinoma. Nature 534:407-411